Electric watch



Dec. l5, 1953 F. KOEHLER 2,662,366

ELECTRIC WATCH Filed Oct. 19, 1951 3 Sheets-Sheet l mills FIG. a

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ELECTRIC WATCH Filed Oct. 19, 1951 5 SheeS-Sheefl 2 INVENTOR FREDKOEHLER ATTORNEY Dec. 15, 1953 F, KOEHLER 2,662,366

ELECTRIC WATCH Filed OC). 19, 1951 3 SheelS-'Sheet 3 FIG. 6

INVENTOR FR ED KOEH LER ATTORNEY Patented Dec. 15, 1953 ELECTRIC WATCHFred Koehler, Lancaster, Pa., assignor to Hamilton Watch Company,Lancaster, Pa.

Application October 19, 1951, Serial No. 252,079

6 Claims.

This invention relates to a watch adapted to be motivated by a magneticimpulse and where the balance wheel serves both as the driving elementand the regulating element.

The object of the present invention is to provide an electric watchwhich utilizes an absolute minimum of power.

Heretofore, attempts have been made to make electric watches which areoperated by a small flashlight battery for a period of a year but suchattempts have failed because of the large expenditure of power requiredin the running of the watch. Y

The present invention overcomes that difficulty by utilizing every lastparticle of power delivered by the magnetic impulse to advance the handsof the watch.

It is a further object of the present invention to provide a toothedgear wheel adapted to be engaged by a spring to advance the mechanism inhalf second increments and to actuate at the same time the contactmaking spring.

It is a further object of the present invention to utilize the motion ofthe contact making spring for wiping and cleaning the contacts and thereturn resiliency of the spring assists and finally positions the handsof the watch by impinging against the teeth of the toothed gear.

It is a further object of the present invention to locate the positionof the contact making spring so that its engagement with the toothedgear assures the correct position of the teeth of the toothed gear forengagement with the advancing spring of the balance wheel.

The invention is shown in the accompanying drawings in which:

Figure l is a top perspective view of the watch.

Figure 2 is a similar view with the balance wheel assembly removed.

Figure 3 is an enlarged view of the balance wheel assembly.

Figure 4 is a detail View showing the engagement of the advancing springwith the toothed gear and the engagement of the toothed gear with thecontact making spring.

Figure 5 is a diagrammatic View demonstrating the angular relation atthe contact points of both the advancing spring and the contact makingspring.

Figure 6 is an enlarged view showing a section of the movement from thefront.

Referring particularly to Figures l and 2, a base 1 has mounted thereona plate 8 on which is carried a pair of magnetic coils 9 and I0. PostsII and I2 secured to the plate 8 carry a bridge I3 which supports thebalance wheel assembly. A regulator I4 similar to that used forregulating the effective length of the hairspring is mounted as usual. Asetting stem I5 connects with a train I6 to set the hands (not shown) inthe usual manner. The train is of the usual type with the exception ofthe toothed gear l1 and is not shown except as between the twosupporting plates.

Current enters from the wire I8, passes through the coil 9, then by wireI9 to the coil 1I) and from coil I0 to the contact supporting posts 20.An insulated block 120 serves to prevent shorting of the current andinsulates the supporting posts from the plate 8.

The supporting posts 20 carry contacts 2l which are shown here induplicate but which could be any number. A contact making spring 22 issupported by a clamp 23 carried on the train I6 and itself supports apair of contacts 24 for engagement with the contacts 2l. A carboloy cam25 is carried centrally of the spring -22 for engagement with the teethof the toothed wheel I1. This engagement will be explained in detaillater.

The posts II and I2 support a bridge i3 which carries the balance wheelstaff 26, which is sup ported in the usual bearings 27. The balancestaiT is formed with a pair of integral annular anges 28 and 29 whichare formed with flattened sides 30 and a notch 3|. The balance wheel hasthe usual hairspring .'32 and also carries an additional coil spring 33,the lower end of which extends through the notches 3l of the flanges 28and 29 between which the toothed gear Il moves into the path ofoscillation of the end 34 of the spring 33.

Referring particularly to Figure 3, the balance Wheel assembly is shownwith a magnetic arm 35 passing between the poles of the magnets 36. Thedotted position of the bar as shows the inv stant at which the contacts2| and 24 make and the surge of magnetic attraction through the ends ofthe cores 36 swings the arm 35 through the balance wheel assembly untilthe point 3l of one of the teeth 39 of the toothed gear Il passes thecenter point of the carbcioy cam 25. The tension of the spring 22 whichhas been pushed into the dotted line position shown in Figure 5 causesthe cam 25 to advance the toothed gear I1 sufficiently to permit saidcam 25 to drop beside the tooth, thus breaking the contact. This is doneat the moment when the edge of the bar 35 is opposite the edge of theend of the cores 35. The ad vancement oi the toothed gear I1 isaccomplished by contact with the edge of the teeth by the end 34 of thespring 33. Referring to Figure 4, movement of the annular ilanges 28 and29 is, of course, oscillatory and when moving in the direction of thearrow, the spring 34 engages the teeth of the gear Il advancing thetooth to move the contact 24 into contact making position. Thesubsequent movement of the spring arm 22 bears against the flat of theteeth 38 and holds the teeth for engagement with the wire 34 at theexact right moment.

Referring particularly to Figure 6, it is thought that the action of themovement may be clarified by pointing out the cycle of movement in thisview. The balance wheel 39 carries on its staff 26 the flanges 28 and29. These flanges are formed with angled notches 3l which are aligned,shown in Figure l, and receive the end 34 of the coiled spring 33. Aring 40 engages the perimeter of the flanges 28 and 29 to retain the end3d of the spring 33 within the notches 3 i Located between the flanges28 and 29 is the tooth driven wheel il. By referring to Figure 4 it isclear that motion of the balance wheel 38 will bring the end 34 of thespring into engagement with the teeth of the wheel Il when moving in acounter-clockwise direction, and when moving in a clockwise direc tionthe end of the spring 34 will ride over the teeth of the wheel I1 bymoving in the angled notches 3|, the spring end 34 being retained in thenotches by the ring 4D. This construction permits the end 34 to serve asa rigid advancing bar when moving in a counter-clockwise direction and aresilient spring end when moving in a clockwise direction.

By referring further to Figure 5, the advancement of the toothed Wheell'l by the spring end 34 moves the cam 25 to close the contacts between24 and 2l. Due to the length and flexibility of the spring 22, thecontact 24 wipes slightly the face of the contact 23 during the contactmakn ing motion. This slight wiping action is sufficient to keep thepair of contacts free of oxidation. The motion of the wheel l1, however,through the action of the spring end 32 is such that as the cam ridesover the tooth 3'! the action of the spring Z2 urges the toothed wheelIl in a clock wise direction until the cam drops into the posi'- tionshown in Figure 5. With the dropping of the cam into position in Figure5, the pressure of the spring 22 is directed toward the center of thewheel Il and against the angled surface of the tooth. This pressuretends to seat the cam 25, as shown in Figure 5, with contact at twosurfaces of the toothed wheel, thus holding the toothed Wheel in theexact proper position to be engaged by the end 34 of the spring 33 onthe next swing of the balance. Each of the teeth on the wheel Il coversan arc of 15. The rotation of the wheel I1 caused by the pin 34 amountsto 11 of this arc, while the remaining 4 of arc is caused by thepressure of the cam 25 against the upper edge of one of the teeth (asshown in dotted lines in Figure thus utilizing the resiliency of thespring 22 to return to its normal position. By reason of the length ofthe spring 22 and the distance between the cam 25 and the contact 24,the movement at the end of the spring where the contact 24 is mounted israpid. This quick make and break also serves to prevent anycarbonization of the contacts which is also assisted by the slightwiping action of the contacts across each other also caused by thelength and ilexibility of the spring 22, It will thus be seen that thework done against the spring 22 in closing the contacts between 2| and24 is partially recovered by the movement of the wheel Il through theaction of the cam 25 bearing against the tooth 31. By utilizing thisenergy of the spring and by maintaining the movement free of extraparts, it is possible to run such a Watch on the smallest flashlightbattery made for periods of six months and upwards.

What is claimed is:

1. An electric Watch movement, comprising a base, an electromagnetmounted on said base, a battery in circuit with said electromagnetcarried by said base, a balance wheel, balance staff rand hairspringassembly mounted for oscillation yon said base, an armature carried bysaid' balance staff adapted to be impulsed at regular intervals by saidelectromagnet, a coil spring secured to said balance wheel andencircling said balance staii and oscillating therewith, the free end ofsaid spring extending downwardparallel to .said balance stad, ofvertically spaced flanges carried by said balance wheel and formed withnotches for receiving the free end of said spring, means for retainingsaid spring end within said notches, a toothed wheel mounted to rotateparallel to said balance wheel and partially within between saidiianges, the teeth of said wheel h ing engaged by said spring end duringthe ocnlation of said balance wheel whereby said wheel is progressivelyindexed, and means actuated by said indexed wheel for making andbreaking said circuit between said battery and said electromagnet.

2. An electric watch movement of the type to be operated on a minimum ofelectric current, comprising a base, a battery carried by said base, anelectromagnet mounted on said base and in circuit with said battery, abalance wheel, balance staff and hairspring assembly mounted foroscillation on said base, an armature carried by said balance staff andimpulsed at predetermined intervals by said electromagnet, a coil springsurrounding said balance staff and connected to said balance staff atone end, the free end o! said spring terminating in a spring finger, apair of vertically spaced flanges carried by said balance stad andformed with notches for receiving the spring nger, a toothed wheeladapted to rotate in a plane parallel to said balance wheel and toextend between said anges and to be engaged and advanced one tooth bysaid spring finger when moving in a counter-clockwise direction, thespring finger retreating in the notches to pass over said teeth whenmoving in a clockwise direction, a spring carrying a pair of contactsfor making and breaking the circuit between the battery and saidelectromagnet, a cam carried on said spring engaging said toothed Wheel,movement of said toothed wheel under the iniluence of said spring fingermoving the cam and its spring to make and break the elec tric circuit,the return spring motion of the cam serving to assist the indexingmotion of the toothed wheel.

3. An electric Watch movement of the type to be operated on a minimum ofelectric current, comprising a base, a battery carried by said base, anelectromagnet mounted on said base and ac tuated by said battery, abalance wheel, balance staff and harspring assembly mounted foroscillation on said base, an armature bar carried by said balance staffand impulsed by said electromagnet at predetermined intervals, a coilspring surrounding said balance staff and connected at one end to saidbalance staff and oscillating with said stall', the free end of saidspring terminating in a downwardly projecting spring finger, a pair ofspaced flanges carried by said balance stal and notched to receive saidspring finger, a toothed wheel adapted to be indexed by said springlinger in one direction, a spring arm, a cam carried by said spring armand engaging the teeth of said indexed wheel, a pair of contacts on theend of said spring arm, a second pair of contacts connected in thecircuit between said battery and said electromagnet mounted in the pathof movement of said spring arm, the indexing of the wheel by said springlinger moving the spring arm through the cam to provide a wiping actionof one pair of contacts over the other pair of contacts.

4.. An electric watch movement of the type to be operated on a minimumof electric current, comprising a base, a battery mounted on said base,an electromagnet mounted on said base and actuated by said battery, apair of stationary contacts connected to said battery, a balance staff,balance wheel and hairspring assembly mounted for oscillation on saidbase, a coil spring carried by said balance staff and oscillatingtherewith having its lower end projected downward to form a springlinger, a pair of spaced lianges carried by said balance staff andformed with notches engaging said spring finger, said flanges havingrims to retain the linger within the notches, a toothed wheel mountedfor rotation in a plane parallel to said balance wheel and in the pathof movement of said spring finger, said toothed wheel to beprogressively advanced by said spring linger during the oscillation ofthe balance wheel in one direction, the return oscillation forcing thelinger up into the notches and permitting said linger to ride past theteeth without disturbing the toothed Wheel, a spring carrying a pair ofcontacts, an arcuate faced cam mounted on said spring and engaging thetoothed wheel, motion of the toothed wheel through contact with thespring linger riding the arcuate cam to the top of one of the teeth andengaging the spring carried contacts with the stationary contacts tocomplete the electric circuit, pressure of the spring through thearcuate faced cam acting on the teeth to slightly index the toothedwheel to a predetermined position.

5. An electric watch movement of the type to be operated on a minimum ofelectric current, comprising a base, a battery carried by said base, anelectromagnet mounted on said base and in circuit with said battery, abalance wheel, balance staff and hairspring assembly mounted foroscillation on said base, an armature carried by said balance staff andimpulsed at predetermined intervals by said electromagnet, a coil springsurrounding said balance stall and connected to said balance stall atone end, the free end of said spring terminating in a spring linger, apair of vertically spaced lianges carried by said balance staff andformed with notches for receiving the spring linger, a toothed wheeladapted to rotate in a plane parallel to said balance wheel and toextend between said lianges and to be engaged and advanced one tooth bysaid spring linger when moving in one direction, the spring lingerretreating in the notches to pass over said teeth when moving in theopposite direction, contact means in said circuit, a spring associatedwith said contact means for making and breaking the circuit, a camcarried on said spring engaging said toothed wheel, movement of saidtoothed wheel operating the contact means through said spring linger,the return spring motion causing the cam to assist the indexing motionof the toothed wheel.

6. An electric watch movement of the type to be operated on a minimum ofelectric current, comprising a base, a battery mounted on said base, anelectromagnet mounted on said base and actuated by said battery,stationary contact means connected to said battery, a balance staff,balance wheel and hairspring assembly mounted for oscillation on saidbase, a coil spring carried by said balance staff and oscillatingtherewith having its lower end projected downward to form a springlinger, a pair of spaced flanges carried by said balance stall andformed with notches engaging said spring linger, said lianges havingrims to retain the linger within the notches, a toothed wheel mountedfor rotation in a plane parallel to said balance wheel and in the pathof movement of said spring finger, said toothed wheel to beprogressively advanced by said spring linger during the oscillation ofthe balance wheel in one direction, the return oscillation forcing thefinger backward in the notches and permitting said linger to ride pastthe teeth without disturbing the toothed Wheel, a spring having contactmeans thereon adapted toengage the stationary contact means, an arcuatefaced cam mounted on said spring and engaging said toothed wheel, motionof the toothed wheel through contact with the spring finger riding thearcuate faced cam to the top of the teeth causing the spring carriedcontact means to contact the stationary Contact means to complete theelectric circuit, the resulting pressure of the spring through thearcuate faced cam acting on the teeth to slightly index the toothedWheel to a predetermined position.

FRED KOEHLER.

References Cited in the file of this patent UNITED STATES PATENTS NumberName Date 1,175,610 Cove Mar. 14, 1916 FOREIGN PATENTS Number CountryDate 855,412 France Feb. 12, 1940

